A plurality of substances, for example medicines or food additives such as vitamins, proteins, anti-oxidants or even vegetable additives, as an aqueous solution, aqueous suspension or emulsion have a potency that decreases rapidly with time. In particular in the area of sport and wellbeing, these types of products are preferably commercialised in liquid form, often in pre-packaged beverage bottles. As a result of the unavoidable transport and storage times, in the majority of cases these types of beverages no longer provide the consumer with the originally desired effect or only provide it in a limited manner. Many of the above-described substances, however, maintain their initial properties very well in dried form, for example as capsules, pastilles, tablets, pills, granulate or powder without forfeiting their original potency. Consequently there are already beverage containers on the market which have at least two separate chambers, one chamber containing the liquid and the other chamber containing the actual active substance in dried form or as a concentrated liquid or paste. Not until directly prior to use are the contents of the two chambers mixed and the beverage consumed. In the case of a variant of these types of beverage bottles, the substance, which is typically dried or is present in concentrated form, is situated in a chamber provided in the closure cap, whilst the liquid which makes up the main proportion of the beverage is situated in a conventional manner in the main container.
Applicant's international patent application WO 2014/023818 describes a closure cap for a container, said closure cap having an inner chamber in which a substance to be protected is able to be kept protected from environmental influences during storage and prior to use is able to be discharged into a container where the closure cap is provided with a clear and easily understandable activating mechanism and which can be produced in a particularly simple and cost-efficient manner.
The closure cap of WO 2014/023818 comprises a cap housing which includes a substantially cylindrical recess which has a top opening and a bottom opening, wherein the bottom opening is closed by means of a membrane, a plunger which comprises a cover and a substantially cylindrical lateral surface which extends downward from an underside of the cover, wherein the lateral surface engages in the top opening of the recess of the cap housing and has an outside diameter which corresponds substantially to the inside diameter of the recess, and a chamber which is defined by the recess of the cap housing and the plunger which engages in the recess by way of its lateral surface, the plunger and the cap housing being arranged so as to be movable relative to one another between a first, non-active position, in which a bottom edge of the lateral surface is arranged above the bottom opening of the recess of the cap housing and a second, activated position, in which the bottom edge of the lateral surface opens the initially closed bottom opening.
In the embodiment of WO 2014/023818, the opening of the bottom opening can be effected by providing the bottom rim of the plunger with a sharpened edge or at least a tip or point which is able to pierce the membrane when the plunger is moved into the second, activated position. In order to be easily piercable, the membrane has to be relatively thin and therefore lacks structural rigidity to allow for a large opening at the bottom of the cap to be formed, preferably an opening which essentially corresponds to the bottom opening of the recess. If, however, the membrane is provided with enough structural rigidity, the forces required for piercing he membrane increase and handling of the closure cap becomes more and more difficult. While a small opening will generally be sufficient to discharge a liquid, discharging of powders or granulate or other larger materials will generally require a larger opening which is reliably formed upon activation of the closure cap. Specifically, for medical applications, where reliable dosing of the substance contained in the closure cap is required, it is important to provide an opening which allows essentially complete discharge of the substance contained in the closure cap.